Black Iron BTU Capacity

RidgeReaper56

Hello everyone,

I am running into an issue where I need to know the BTU capacity of 1-1/4" SCH40 Black Iron pipe. The pipe is in a hot water heating system. I've been looking for charts online and I can't find what I am looking for. Does anyone here know of any charts, or can provide information for what I am looking for.

Thank you

Snowmelt

How many btu are we talking about…?

Snowmelt

120 for 1-1/4.
200 for 1-1/2
I think it’s a little more but that’s what I just found

RidgeReaper56

Are you able to share your source with me?

Snowmelt

Just google black pipe water btu….. nothing special

dopey27177

google this

heat loss of 1 1/4" schedule 40 black steel pipe

Jake

EBEBRATT-Ed

If you looking for water flow btu capacity 1 1/4" will carry 16 gpm max. If your system has a 20 degree temperature drop you are good for 160,000 btu/hour (10,000 btu/gpm circulated)

RidgeReaper56

Thank you all for your help. I was over thinking my Google search.

Alan (California Radiant) Forbes

This calculator will give you GPM as a function of feet per second.

https://www.tlv.com/global/US/calculator/water-flow-rate-through-piping.html

Zman

BTU/Hr = GPM x Delta T x 500 (constant)
Many designers use GPM at 4 ft/sec and a Delta T of 20 degrees.
For "speed math" you can take the pipe capacity at 4 ft/sec and just move the decimal.
16 GPM x 20 X 500 +160,000

hot_rod

The engineering toolbox has a lot of info for sizing pipes, here is a type L copper example and steel pipe 2" and up.

Pipe size over 2" is sized by pressure drop, not the flow velocity. Pipe under 2" stay at or below 4 fps velocity.

So the table shows max. flow rates, now determine the delta T you will design around to get heat carrying capacity.